As semiconductor fabrication technologies progress to smaller feature sizes such as 65 nanometers, 45 nanometers, and below, immersion lithography methods are being adopted to address the problems associated with such fabrication. During an exposure process using an immersion lithography system, evaporation effects in various locations and other effects associated with immersion fluid will cool down a wafer in process. A heater has been included and sealed in the immersion hood for temperature compensation. However, the sealed opening of the immersion hood directly contacts the immersion fluid. The sealant of the opening becomes a particle source and introduces contamination to the immersion fluid, the immersion lithography system, and further contaminates the wafer in process and/or cause lithography exposure defects on the wafer.